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Hippocrates, Galen and Paracelsus: Game-Changers in the Field of Modern Medicine

Archaeological studies show that humans have been practicing medicine as far
back as 60,000 years ago, using plants such as cannabis and opium poppies to
treat the sick and unwell. The science of medicine progressed over the years but
remained focused on spirituality and followed a more ‘one size fits all’ approach,
with different illnesses being treated in largely the same manner (Pan 2014). In
this blog, I will introduce you to three influential people, who were driving forces
in the creation of modern medicine.

Hippocrates: The Father of Modern Medicine.
Born: 460 BC, Greece
Hippocrates was a pioneer of modern medicine, believing that diseases were caused naturally, rather than by religion, superstition or myth. Hippocrates practiced medicine for his whole adult life and ensured he would make a lasting contribution to human health and healthcare by writing down his thoughts and findings about various medical subjects; around 60 lectures, medical notes, research and text books were compiled by Hippocrates (and probably his colleagues and students) and named The Hippocratic Corpus (Totelin 2021). One of the most notable and influential documents within the corpus is The Hippocratic Oath, which defines ethical and moral medical practice. The contents of the oath are still regarded as useful and important all these years later and derivatives of The Hippocratic Oath are still used today by medical students during their graduation ceremonies (Clark 2018). Arguably, the main message of the oath can be boiled down to just one line: “I will enter to help the sick, and I will abstain from all intentional wrong-doing and harm”.
As well as being a pioneer of medical ethics, Hippocrates introduced the idea that medicine must be administered dependent on observation, reason and prior experience (Kleisiaris 2014). He knew that to effectively treat someone, a diagnosis must be made and the correct treatment must be chosen. It is remarkable how much of what Hippocrates was advocating for, nearly 2500 years ago, remains as the cornerstone of modern medicine today!
Greek Galen: The Father of Anatomy
Born: AD 129, Greece
Galen moved to Greece’s capital, Rome, to promote Hippocratic teaching but also developed his own scientific disciplines; most notably, he brought the importance of anatomy to the forefront of medicine. As the dissection of human cadavers was prohibited, Galen instead used dead animals to learn about anatomy (Sternbach 2001). Although using animals as a substitute for humans led to certain mistakes – a dog’s uterus and a woman’s uterus are not the same – he still made seminal breakthroughs in understanding the human body. For example: he proved that our voice is controlled by our brain, he discovered that veins carry blood instead of air and delineated the difference between sensory and motor nerves (Dedo 1970, Aird 2011, Porras-Gallo 2018).
Interestingly, Galen worked as a physician for gladiators and had a remarkable success rate, with only 5 gladiators dying while he was on post, compared to 60 in his predecessor’s time (Standring 2016).
 It seems Galen was quite the showman; he performed public demonstrations of bodily anatomy and successfully treated rich and famous patients, who had been deemed incurable by other doctors. Galen is even reported to have fled Rome as he felt his colleagues were intolerable with jealousy. Although, a more likely explanation is that Galen ran away from Rome to escape the plague, which was beginning to ravage the city (Wasson 2019).
Swiss Paracelsus: The Father of Toxicology
Born: AD 1493, Switzerland
Swiss-born Paracelsus is hailed The Father of Toxicology for his pioneering use of minerals and chemicals in medicine. His principle belief was that ‘like cures like’, i.e. to cure a toxin in the body, you must treat the body with a toxin. Thankfully, he did caveat this message by realising that the dose at which the toxin is delivered is important (Borzelleca, 2000). Paracelsus tested the use of chemicals on experimental animals to study their toxicological profiles. After testing, he advocated for the use of mercury, lead and arsenic, amongst other substances (Michaleas 2021). We know now that mercury and lead are not the type of substances you want to be messing around with or indeed ingesting as a medicine, but over 1500 years ago, many people believed these toxins to be the pinnacle of modern healthcare. Arsenic, however, is still used today to kill certain parasites and arsenic trioxide is used to treat a specific type of leukaemia (Wang 2015).
Indeed, many cancers are treated with medicines which follow Paracelsus’ idea that toxins kill toxins; the main chemicals used in chemotherapy are derivatives of mustard gas and radiotherapy uses ionising radiation to target tumours (Smith 2017). Although his use of inorganic elements stirred controversy amongst his peers, it is certain that Paracelsus bridged the gap between chemistry and medicine and made great contributions to the study of toxicology.

Although some of the ideas of Hippocrates, Galen and Paracelsus seem crazy and dangerous now, we must remember that they were working in a pre-technology, pre-internet era. They managed to influence the world of medicine, despite the dissemination of information being solely through word-of-mouth and written works. These days, medicine moves at an astonishing pace, with new medicines being researched, developed and trailled in patients for even the rarest of conditions. We just have to look at the remarkable speed at which the COVID-19 vaccine was released to see how far modern medicine has come, but I believe that the ideas and philosophies of Hippocrates, Galen and Paracelsus built the foundations that modern medicine stands on today.

~This article was written by Katie Lowles for LIVE with Scientists. All views belong solely to the author. ~ 

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